Patent Co-operation Treaty publication No. WO93/11866 discloses an apparatus and method for deposition of droplets, for instance for printing, using a high resistivity carrier and chargeable particles in the carrier. The particles agglomerate during droplet formation and can be ejected from an ejection location on demand.
Deposition materials or inks for such equipment are disclosed in Patent Co-operation Treaty publication Nos. WO95/011414 and WO96/10058. All of these deposition materials or inks have particles of insoluble material which are agglomerated in the ejection apparatus using electrostatic forces.
It is now surprisingly been found that it is possible to prepare deposition materials, such as inks, which do not contain insoluble particles but which contain active or desired ingredients in solution which may also be ejected as droplets on demand from an apparatus of the type as discussed above.
It is an object of this invention therefore to provide inks which do not contain particles but which can be ejected from the apparatus discussed above.